2 files changed, 47 insertions, 0 deletions
diff --git a/tests/012/ifa.expected b/tests/012/ifa.expected
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/tests/012/ifa.expected
diff --git a/tests/012/ifa.tl b/tests/012/ifa.tl
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index 00000000..d659399e
--- /dev/null
+++ b/tests/012/ifa.tl
@@ -0,0 +1,47 @@
+(defmacro error-to-sym (expr)
+ ^(catch ,expr
+    (error (cond) :error)))
+
+;; test framework for ifa uses ifa!
+(defmacro test (:env env expr expected)
+ (catch
+   (let ((expr-expn (macroexpand expr env)))
+     ^(ifa (not (equal (error-to-sym ,expr-expn) ',expected))
+           (error "test case ~s failed: produced ~s; expected ~s"
+                  ',expr it ',expected)))
+   (error (exc)
+          (unless (eq expected :error)
+            (error "test case ~s failed to expand: expected is ~s" expr expected)))))
+
+;; "it" is (+ 2 2)
+(ifa (> (+ 2 2) 0) (* it 2))
+
+(test (ifa (> (+ 2 2) 0) (* it 2))
+  8)
+
+;; "it" is (* x x)
+(test (let ((x 7))
+    (ifa (>= (* x x) 49)
+      (isqrt it)))
+  7)
+
+;; ambiguous: is "it" x or is "it" y?
+(test (ifa (> x y) (print it)) :error)
+
+;; "it" is (+ 3 (* 2 x))
+(test (let ((x 5))
+    (ifa (< 0 (+ 3 (* 2 x)) 20) (* 100 it)))
+  1300)
+
+;; "it" is (length '(a b c d))
+;; Intuition: it" could also be '(a b c d)
+;; TODO: deal specially with chains of unary functions.
+;; How about it = (length ...), itt = '(a b c d)
+(test (ifa (not (oddp (length '(a b c d)))) it)
+  4)
+
+;; "it" is y because %x% is constantp
+(test (symacrolet ((%x% 42))
+      (let ((y 41))
+        (ifa (> %x% y) it)))
+    42)